Automatic tong extracting and re-setting mechanism



Jan. 1, 1957 E. E. ECKSTEIN AUTOMATIC TONG EXTRACTING AND RE-SETTING MECHANISM Filed Oct. 22, 1953 3 Sheets-Sheet l INVENTOR. ERNEST 556K575 Ill'l'llllll.

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FITTOBNE YD Jan. 1, 1957 E. E. ECKSTEIN AUTOMATIC TONG EXTRACTING AND RE-SETTING MECHANISM Filed 001;. 22, 1953 3 Sheets-Sheet 2 mum/0Q EENEJT E. ECKJTf/N Jan. 1, 1957 E. E. ECKSTEIN 2,776,164

AUTOMATIC TONG EXTRACTING AND RE-SETTING MECHANISM Filed Oct. 22, 1953 3 Sheets-Sheet 3 $1 .6 .7 M ea 5 g M 32 I I5 I5 llvvflwoe EBNEJT E CK5TEIN 70 nrroenEvzj AUTOMATIC TONG EXTRACTING AND RE-SETTING ll IECHANISM Ernest E. Eckstein, Elgin, Oreg.

Application October 22, 1953, Serial No. 387,693 4 Claims. (Cl. 294110) This invention relates to tongs and tong releasing and resetting mechanism as used in connection with log handling equipment. More particularly, the invention has reference to an automatic tong control mechanism for use with present day cable and cable winding hoists as employed for the handling of logs by means of tongs; the present apparatus being especially useful for the cold decking of logs but not to be confined thereto.

It is the principal object of the present invention to provide a tong releasing and resetting mechanism which is in the nature of an improvement upon the mechanism described and illustrated in my co-pending application,

filed under Serial No. 302,707, on August 5, 1952, and

which application matured into United States Patent No. 2,656,212 on October 20, 1953.

More specifically, the present invention resides in the provision of a simplified, effective and automatically operating tong extracting and tong resetting mechanismv designed for use in connection with a cable and cable winding drum in the same manner as disclosed in the above mentioned application but which, by reason of improved features of construction, comprises fewer parts; is lighter in weight; is simplified in its operation and less expensive to manufacture, yet practical and entirely satisfactory in its use.

Further objects and advantages of the present invention reside in the improved details of construction and combination of parts, and in their mode of operation as will hereinafter be fully described.

In accomplishing the above mentioned and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective view of the tong releasing and resetting mechanism of the present invention as associated with a hoisting cable and a pair of tongs which are here shown applied to a log.

Fig. 2 is a similar view of the device as seen from the side opposite that seen in Fig. 1.

Fig. 3 is a side view of the lower end portion of the device, and showing the mode of engaging the open tongs with a log in a resetting operation.

Fig. 4 is a side view of the mechanism as seen from its latch bar mounting side.

Fig. 4a is an elevation of the opposite side of the housing, showing a log as suspended by the tongs.

Fig. 5 is an enlarged horizontal section of the device, taken on line 55 in Fig. 7.

Fig. 6 is a longitudinal section of the device showing the normal relationship of parts while a log is being supported and conveyed by the tongs.

Figs. 7 and 8 are similar sectional views, illustrating sequential operations for the extraction of the tongs.

Fig. 9 is a detail showing in side view, a part of a latch release lever and the adjustable releasing eccentric associated therewith.

Referring more in detail to the drawings:

nited States Patent 0 The mechanism of the present invention, as used in Patented Jan. 1, 1957 combination with a pair of tongs and a hoisting cable, comprises a rather elongated, tubular housing 10. Preferably this housing is rectangular in cross-section and is open from end to end as shown in Fig. 6. It might well be fabricated from angle ir;n members, as disclosed in my above mentioned pending application or it might be cast as an integral piece. In apparatus now in use, the housing 19 is about twenty-six inches long and has an inside passage that is three inches square in its horizontal dimensions.

For purposes presently understood, the housing is formed on each of its four sides, and extending the full length thereof, with laterally spaced, parallel flanges. For purpose of explanation, in Fig. 5, the four sides of the housing have been designated respectively by reference letters A, B, C and D, and the parallel flanges as formed on these four sides, respectively, have been designated by reference letters aa, b-b, c-c and d--d. These flanges serve as mounting means for various parts or mechanisms located between them, and also they serve to protect these parts against damage in the rough use to which the device is subjected.

Slidably contained in the tubular housing 10 are the overlapping inner end portions of two elongated metal bars, designated respectively by numerals 12 and 13. in the present device, wherein the housing is about twentysix inches long, the bars 12 and 13 are each about thirtytwo inches long, about one inch thick and three inches wide and each has a part thereof freely movable endwise in the housing between definite limits as presently explained.

The bar 12 extends from the upper end of the housing 10 and the bar 1 3 extends from the lower end thereof. On adjacent side faces of their overlapped inner end portions, the bars 12 and 13, are equipped, respectively, with integral blocks or lugs 12x and 13x, that are adapted to engage one against the other, end to end, as shown in Figs. .6 and 8, thus to form a load lifting connection between the two bars. However, the two bars, under certain conditions presently explained, can move endwise relative to each other within the housing 10, as indicated by their showing in Figs. 6, 7 and 8.

At its upper end, the bar 12 has a U-shaped loop forming member 15 welded or otherwise attached thereto and to this loop the outer end of a hoisting cable 16 is attached; it being understood that the cable is extended to the loop from the cable Winding drum of a hoisting machine, or winch of any suitable kind that may be designed or used for the lifting and loading of logs. For example, the hoisting engine, not herein shown, may be any boom type loader commonly used in logging and sawmill operations.

At its lower end, the bar 13 has a circular loop 18 welded thereto. Applied through the loop 18 are clevises 19 and 19' and these pivotally connect the loop 18, as seen in Fig. 4, with the upper ends of a pair of tongs 20; these tongs being of the kind normally used for log handling purposes and its jaws are equipped with inturned, pointed teeth 20' as herein shown. The tongs are permitted, by reason of this means and manner of attachment to the loop 18, to be fully opened and closed, and yet will retain their transverse relationship to the housing 10 as seen in Fig. 1. Under weight of a log, the jaws of the tongs, if properly applied, will tend to close together, thus to maintain their 'hold on the log. Usually the teeth embed themselves in .the log to substantial extent and require effort to extract them.

It will be observed, by reference to Figs. 6, 7 and 8, that the upper end of housing 10 is partially closed by a block 24 that is welded thereto in a manner to leave an opening sufiicient for free sliding of bar 12. Likewise the lower end of the housing is closed by a block 25,

leaving an opening for passage of bar 13. These stops also limit the relative endwise movements of bars and housing.

it will be understood further that, when the bars 12 and 13 are in such position that their inner end lugs 12x and 13x are abutted or hooked together, for example as seen in Fig. 6, they serve as a connecting linkage between cable 16 and tongs 20 through which the load sustained by the cable can be lifted; a load, in the form of a log 28, is shown in Figs. 1 and 2.

In the usual log handling operation where a hoisting cable is attached directly to the tongs, it is a dificult and a dangerous task to manually extract the points of the tongs from the log. The present mechanism has been designed to make extraction easy and to eliminate the extra workman heretofore required for this job. Tong extraction is controlled entirely through the hoisting cable 16, and requires no extra manual help either for the extraction of the tongs or for their re-setting. Extracting of the tongs from a log is herein effected through use of two flexible cables 30 that are pivotally attached at their lower ends to flanges 31 that extend outwardly from the tong jaws, and are attached at their upper ends to the lower ends of diagonally opposite flanges of the housing as by the means designated at 32. A plurality of vertically spaced holes 33 are formed along the flanges to provide for mounting the members 32 at the most practical location to provide a limited amount of slack in the cables when the tongs are set in a leg as in Fig. l and the log is in suspension,

The release of the tongs from a log through the me diacy of the hoisting cable 16 is made possible in the present instance by the provision of means for term porarily establishing tong pulling connections through the two cables 30 instead of through bar 13, and in doing this, providing a limited amount of slack, or lost-motion, in the connection between the cable and tongs as provided through the bars 12 and 13. This transfer of the tong lifting connection from bars 12 and 13 is made possible by use of a latch mechanism which provides for establishing a direct connection between bar 12 and the housing 10 after the desired lost motion or slack has been provided in the connection as normally made through bars 12 and 13. This latch mechanism will now be described with reference to the showing of parts in Figs. 4 to 8.

Welded or otherwise fixed to the upper end portion of the bar 12 through the mediacy of a spacer block 38, is a fiat bar 40 which is substantially coextensive with bar 12 and which extends therealong, but outside of the housing 10 and between the flanges a-a thereof, as noted in Figs. 4 and 5. Welded to the outer face of bar 40 directly across its lower end portion, is a lug or stop 41. Located between the flanges, a a, and pivotally mounted on a horizontal cross pin 42, extended therethrough about midway between the upper and lower ends of the housing, is a downwardly and inwardly directed latch bar 4-4, the lower end of which is adapted, upon the bar 12 being fully telescoped into the housing, and the bar 40 being moved downwardly accordingly, to be engaged against the top of the stop 4-1 thus to provide a positive lifting connection between the bar 40 and the housing 16; the bar 49 being attached to bar 12 and cable 16.

The latch bar 44 is at all times yieldingly urged to ward latched or holding position by an inverted U-shaped spring 50, disposed under compression between the latch bar and a cross-plate 51 that extends between and is welded to the flanges a-a; the spring being held in place by a bolt 52 that is fixed in the plate 51 as well shown in Fig. 6.

As a means for effecting the unseating of the latch 44 from holding contact with the bar stop 41 to release this holding connection when such is desired, I have provided the release mechanism which is shown in Figs. 6, 7 and 8. This mechanism comprises a pair of links 60-60 that extend substantially horizontally, at opposite sides of the housing 10 passing freely through openings 61 provided therefor in the flanges b!) and d-d at opposite sides of the housing, as shown in Fig. 5. A horizontal pin 62 joins the ends of these links at the latch side of the housing, passing through openings 63-63 provided therefor in flanges a-a, just outside of the lower end of the latch bar, and resting in an upwardly opening notch 64 formed in a lug 65 that is fixed to and extends outwardly from the lower end of latch bar. The openings 63 through which the pin 62 passes are of such size as to not interfere with the necessary longitudinal shifting of the links, or a required amount of up and down action as will presently be explained.

At their ends opposite those which mount the pin 62, the links 60-60 are joined by a cross-pin 68. This pin passes through openings 669 in the flanges C-(:, and pivotally through the lower end of a latch release lever 70 which is located between the flanges cc as seen in Fig. 6. The lever 70 is pivoted on a pin 71 that extends between the flanges 0-0. It has a bifurcated lower end portion and these two leg portions are laterally spaced and the pivot pin extends through their lower end portions. The openings 69-69 in flanges cc are of such size as not to interfere with the oscillating action of the lever presently described.

The pivot pin 71 is located above the level of the pin 68, and the upper end of the latch release lever 70 is directed inwardly and through a vertical slot 72 formed in the adjacent side wall of the housing 10. Extended upwardly and outwardly from the lever 76 between its ends, is an integral arm 73 to which one end of a coiled spring 74 is attached, under tension. The other end of the spring is attached to a clip 75 on the side wall of the housing at a higher point, thus at all times the spring operates to yieldingly urge the lever 70 toward or hold it in that position in which it is shown in Fig. 8. If the bar 13 is in a lowered position in housing 10, the upper end of the lever will extend into the housing 10 through the elongated wall slot 72 as seen in Fig. 8.

It will be understood that with the parts in position of Fig. 8, the upward movement of bar 13 in the housing 10, will cause the lug 13x at its upper end to engage the inner end of lever 70 and rock the lever on the pivot pin 71. In doing this, the links 6( 60 are shifted endwise to the left, and the cross pin 62 then seated in the notch 64 in lug 65, is caused to unseat the latch 44 from lug 41, thus permitting the housing 10 to drop downwardly relative to the bars 12 and 13.

After the links 6060 are shifted endwise to the left sufficient to unseat the latch 44 from lug 41, continued endwise movement of links 60-60 causes the enlarged cam portions 60x on the under side of the links at their ends below pin 68 to contact the eccentric sleeves 90, thus moving the outer end portions of the levers upwardly, and lifting cross pin 62 out of notch 64 and holding it in the clear until after the next latch engaging operation. During the following extracting operation the bar 13 will drop down, thus allowing spring 74 to retract the cross pin 72 until it again drops into notch 64.

Assuming the parts of the device to be so constructed and to be assembled as described, and with the understanding that the tongs 26 have been properly applied to a log, as in Fig. 1, and that the 1051 has been carried by the cable 16 to an unloading position, and has been lowered to a position of easy rest on the cold deck, but that the parts of the device are still in the normal load carrying relationship, shown in Fig. 6, Without any effective slack as yet having been permitted in cable 16, the procedure to automatically effect the extraction or release of the tongs from the log, is as follows:

First, the operator of the hoisting engine causes about one and one-half foot of slack to be payed out in cable 16.

After the first few inches of slack have been-producedin the cable, the bar 13 comes to solid rest by reason of its connection, at its lower end, with the tongs. The upper end of bar 13 up to this time is in contact with the upper end block 24 of the housing and thus operates as a support for the housing 10. But, as additional slack is produced in the cable, the bar 12 moves downwardly into the housing 10 and the latch release bar 40 that is fixed thereto moved downwardly accordingly, ultimately causing the lug 41 on its lower end to pass beneath and beyond the lower end of the latch lever 44, whereupon the spring 50 causes the latch 44 to snap into position for holding contact with the top side of the stop. The parts are now in the position shown in Fig. 7. In this view it is to be noted that a lost motion connection has been established between bars 12 and 13 by reason of their lugs 12x and 13x being separated to the full extent permitted by the end stops 24 and 25 of the housing 10.

It is desirable, to insure proper operation of the latching mechanism, that the housing 10 be maintained substantially in an upright position while this slack is being produced in the hoisting line. To accomplish this, I provide a coiled, slack take-up spring 78 that is located between the flanges b-b, lengthwise of the housing 10 and is attached under tension at its ends to a lug 79 on the lower end of the housing, and a lug 80 that extends laterally from the upper end of bar 12. This spring 78 operates to pull the bar 12 downwardly and take in the slack as produced in cable 16 after the bar 13 has been lowered to a position of support on tongs or log. This spring will cause the bar 12 to slide into the housing sufficient to engage latch 44 with lug 41 in all positions including vertical. Normally, it will maintain the housing in that substantially upright position that is preferred for engaging stop 41 with latch 44. The tension of this spring is not sufficient, however, to normally lift the housing relative to bar 12.

With the engagement of the latch 44 with the bar stop 41, a direct lifting connection is thereby established between the bar 40 and the housing 10, and about twelve inches of slack will have been produced in the tong lifting connection that had previously existed by reason of the engagement of the blocks 12x and 13x on bars 12 and 13.

With the parts now in position of Fig. 7, the operator then causes the hoisting cable 16 to be wound in and the housing 10 to be lifted through the holding connection effected by latch 44 and bar 40. With the upward lifting of housing 10, the bar 13 begins to slide downwardly from the housing, and the tong release cables 30 attached to the housing, become taut. However, before the lug 12x on bar 12 has moved into contact with lug 13x, these cables pull the jaws of the tongs, to which they are attached, free of the log.

As the housing 10 is thus lifted through the mediacy of bar 40 and latch 44, the bar 13 moves downwardly in housing 10 and ultimately its upper end passes below the slot 72 in the housing wall. This permits the latch release lever 70 to be rocked, under tension of spring 74, to pull the links 60-60 to position of Fig. 8 thus to seat the cross pin 62 in the notch 64 of the lug 65 on the lower end of the latch bar. The device may be held in suspension with the parts thereof in the relationship of Fig. 8 until ready for application of the tongs to another log. At this time, the tongs are open as in Fig. 3.

When the tongs are to be again applied to a log, the housing 10 is swung by cable 16 to a position of suspension over the log and then lowered to cause the tongs to engage the log cross-wise thereof as in Fig. 3. The housing 10 is then lowered slowly by cable 16 and the bar 13 starts moving upwardly in housing 10, thus engaging the inner end of lever 70 and rocking the lever in a manner whereby the links 60-60 are shifted endwise, thus causing the pin 62 to unseat the latch bar 6 44 from the lug 41. With this release of latch 44, the housing 10 drops freely downward to it's full extent relative to bars 12 and 13. This slacks ofi on the cables 30-30 and the jaws of the tongs drop to gripping contact with opposite sides of the log. The parts are now reset to the position of Fig. 6. Then by drawing up on cable 16, the housing will be lifted and the jaw points of the tongs will bite into the log as required for lifting it.

A feature of timing adjustment for release of the latch lever is shown in Fig. 5 wherein it is shown that sleeves are eccentrically mounted on a cross-bolt 91 that extends through flanges c-c. The levers 60-60 normally rest on these sleeves when in position of Fig. 8. By a rotative adjustment of the sleeves the releasing action of pin 62 as effected by the oscillating action of lever 70 can be made more or less sensitive.

When the eccentric sleeves are in a desired position of adjustment they may be locked by tightening the nut on the end of the bolt on which they are mounted.

For lubricating purposes, I find it convenient to mount an oil reservoir 95 in a side wall of housing 70 between the flanges d-d. Oil can be permitted to flow under needle control to the passageway of the housing to lubricate the slide bars 12 and 13.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is:

1. In combination, a pair of load lifting tongs, a hoisting cable and a tong extracting and re-setting mechanism providing a lifting connection between cable and tongs; said mechanism comprising a housing, a pair of bars, each having endwise movement relative to the other and limited telescopic movement into and from the housing; the first of said bars extending from the upper end of the housing and having fixed connection with the hoisting cable and the second of said bars extending from the lower end of the housing and having load supporting connection with the tongs, means providing a direct load lifting connection between said bars when they are fully extended relative to each other and slack in the load lifting connection when not fully extended relative to each other, spring means attached under tension to the housing and first bar and operable to efiect a relative telescopic movement of the first bar into the housing and the taking up of a limited amount of slack produced by the paying out of the lifting cable after a tong held load has been lowered to rest, a latch stop fixed to and movable with the first bar, a latch bar pivoted on the housing and engageable with said stop upon the telescoping of the first bar substantially into the housing under the influence of said spring means, thus to provide a connection for lifting the housing through the mediacy of cable and latch bar, means connecting the housing with the outer ends of the tong jaws and providing for their extraction, and a latch bar releasing means mounted on the housing and functionally operable by the said second bar; said latch bar releasing means comprising an integral three arm release lever that is pivotally mounted on the housing between its ends, with a first arm thereof extended into the path of travel of said second bar, and linkage pivotally connected with a second arm of said release lever and extended to position for releasing engagement with the latch bar incident to the pivotal action of the said release lever that results from the engagement of the first arm thereof by said second bar in its moverneut upwardly from lowered position into said housing, a second spring secured at one end to the housing and secured at its other end to the third arm whereby the arms are caused to rotate about their common pivot and the first arm is moved into position for engagement by said second bar.

2. A combination as recited in claim 1 wherein a yieldable spring means mounted on the housing in position to act against the latch bar to urge it to latching position, a lug on the latch bar formed with a notch, a pin fixed in the adjacent ends of the linkage and said pin seating in the lug notch by that movement of the release lever that results from the second bar moving to a lowered position extended from the housing, and to disengage the latch by that movement of the linkage that is caused by the pivotal action of the release lever incident to the said second bar being moved into the housing from its lowered extended position.

3. A combination as recited in claim 1 wherein the latch bar includes a lug on the engaging end thereof and the lug has a notch formed therein and said linkage includes a pair of links each connected at one end to an arm of the release lever and their other ends extend to opposite sides of said lug, a pin joining the ends of said links adjacent the lug and said pin seating in said notch incident to that movement of the latch lever as actuated 8 by the said second bar moving to a position fully extended from the housing, and to eflect the disengaging of the latch bar incident to that movement of the lever that is caused by the said second bar moving to a position telescoped within the housing.

4. A combination as recited in claim 3 wherein rotatably adjustable eccentrics are mounted on the housing as fulcrum supports on which the said pair of links are slidable under the rocking action of the release lever and said eccentrics providing means whereby the sensitivity of the latch release mechanism may be controlled.

References Cited in the file of this patent UNITED STATES PATENTS 2,656,212 Eckstein Oct. 20, 1953 

